Product category:
Trade effluent monitoring + on-site treatment
News Release from: Siemens Milltronics | Subject: D Hewitt review
Edited by the Processingtalk Editorial
Team on 18 April 2006
Don't be overcharged for effluent
discharge
Don't be overcharged for effluent discharge: David Hewitt, product manager for level at Siemens Automation and Drives, explains how to measure the flow totals of such discharges
Thankfully, the days when industry poured its polluted effluent into the nearest watercourse and ignored the effects are behind us However, the problems of pollution still remain
This article was originally published on Processingtalk on 6 Jul 2005 at 8.00am (UK)
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Environmental regulations now require strict reporting of all discharges, with accompanying fines or penalties.
However - when plant managers take steps to reduce pollution and discharges, they need an effective way to measure their progress.
At one time the only option was to use magmeters, which are expensive and not always practical for many open channel installations.
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The latest Siemens range of ultrasonic transducers for level measurement is delivering accurate and reliable measurement to the water industry
However, accurate measurement of open channel flow is now not only achievable, but simple and cost-effective with the MCERTS approved Siemens OCM III.
When combined with an ultrasonic transducer, it monitors flow and provides data you can use for rainfall/storm water studies, inflow/infiltration studies and sewer system evaluations.
An extensive data log memory permits logging from 31 days of one-minute entries, up to 24 months with daily entries.
Advanced functions include variable data logging.
Under normal flow conditions, the OCM samples flow at a predetermined rate (e.g every 15 minutes) but it can be programmed to automatically sample at a higher frequency during rapid flow rate changes.
This provides a highly detailed profile of a sudden inflow of effluent into the system or storm water flood conditions.
Under steady conditions, the OCM automatically logs less frequently to conserve data log space.
It accommodates AC and DC operation, automatically switching to battery operation for uninterrupted power.
With so many variations of weirs and flumes, flow calculations can be complex, but the OCM makes it easy.
It is fully programmed with calculations for all standard primary devices, including Parshall, Palmer-Bowlus and other flumes, various weir configurations, and BS 3680 European standard.
For unique or non-standard weirs or flumes, the programmable head-versus-flow curve (up to16 points) accurately defines flow rate.
Information can be programmed and downloaded locally by calibrator or PC, or remotely via telemetry.
The OCM has two-way communications via RS-232 with a modem for remote or a direct cable for local connection.
Data logs can be downloaded with Flow Reporter PC software for viewing logged data, or conversion to spreadsheet format.
After installation and calibration, logged data can be downloaded from several locations without ever leaving the office.
It saves time and money while providing important data.
Accurate, verifiable records of flow volumes help users to comply with environmental reporting requirements, track their pollution reduction efforts, and ensure that they are never overcharged for discharge.
The OCM III is one of two products in the Siemens product portfolio which meets the requirements of MCERTS, the other is the HydroRanger 200.
Full details of the Siemens Open Channel and closed pipe flowmeters can be found on our web site.
* Tips for Effective Open Channel Flow Measurement:.
1 Ensure the primary device (weir or flume) is the right type and size for the expected flow rate, and ensure it is installed properly.
Discrepancies from the standard design, dimensions, or set-up will adversely affect the accuracy of flow measurement devices.
Ensure that it is properly cleaned and maintained.
Any build-up of sediment or vegetation can influence flow and flow measurement.
2 Check upstream conditions that may create waves or surging.
Hydraulic jumps, flow pipes or drops in approach pipes located close to the flume can interfere with measurement.
3 When installing flow measurement devices, follow the installation guidelines in the instruction manual to ensure correct set-up and to be aware of any limitations.
4 Field calibration of the primary element will tell you if the actual head corresponds to the head-to-flow calibration information supplied by the manufacturer.
If not, a new curve can be determined through field testing.
This is essential on special applications or non-standard weirs and flumes.
5 Install the head measuring device in a relatively calm, stable portion of the channel.
It should not be positioned in a channel approach that has high velocity of water, turbulence, gates, valves, pumps or a sudden change in section.
6 Make sure the measurement device has been properly zeroed in reference to the primary device.
When the flume is empty, your level sensor should read zero.
* Software Simplifies Flow Monitoring.
Remote monitoring of open channel flow is easy and efficient with Flow Reporter, a Windows-based configuration software and data extractor for use with the MCERTS approved Siemens Open Channel Meter (OCM III).
Flow Reporter lets you monitor and troubleshoot flow readings collected by the OCM quickly and easily from your desktop PC.
It can also be used directly in the field with a laptop.
Flow Reporter saves staff time because technicians no longer need to retrieve data manually from field locations.
Flow Reporter connects to the OCM by modem, so the host computer can be located any distance from the flowmeters.
It lets you check flow rates at your convenience, giving more flexibility for plant operations and work schedules.
It reduces time spent on record keeping and facilitates more accurate reports.
It's easy to install and use-just load the software and, in minutes, you are ready to monitor values or get data logs for one or more OCM controllers, all in the familiar Windows environment.
Flow Reporter uploads data logs from the OCM, reviews past and present data logs in a database environment, exports summary information and data to a spreadsheet, prints daily or monthly reports as required, and lets you view and modify parameters from a remote location.
The programme includes a relational database so you can seek out specific data.
Windows is a registered trademark of Microsoft Corporation.
* Measuring Flow with a Velocity Sensor.
How do you measure flow rate and volume in a channel with no flume or weir? A Siemens VS 100 velocity sensor connected to the Open Channel Meter (OCM III) will do the calculations for you.
The velocity sensor, secured to the bottom of the channel, uses the Doppler effect to measure water speed.
It transmits the information to the VS 100 electronics to be processed and sent to the OCM as a velocity signal.
Using the level measurement and velocity data, the OCM computes the flow through the channel which can be totalised and logged.
This velocity sensor can also be used in a pipe using a screw jack mounting ring to hold the sensor securely in place.
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